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-(No Model.) 2 Sheets-Sheet 1.

. S. BENSUN.

@RUSHING AND GRINDING MILL ,929. Patented Dec. 30,V 1890.

(No Model.) zsheets-Sheet 2. S. BENSON.

GRUSHING AND GRINDING MILL. No. 443,929. Patented Deo. 3,0, A1890.

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UNH-nn STATES PATENT Ormea.

SAMUEL BENSON, OF BU"TE CITY, MONTANA, ASSIGNOR OF ONE-HALF TO JOHN M. MONTGOMERY, OF SAME PLACE.

CRUSHING AND GRINDING MILL.

SPECIFICATION forming part of Letters Patent No. 443,929, dated December 30, 1890.

Application iiled August 12, 1890. Serial No. 361,819. (No model.)

To all whom it may concern:

Be it known that I, SAMUEL BENSON, a citizen of the United States, residing at Butte City, in the county of Silver Bowand State of Montana, have invented a new and useful OrePulverizer, of which the following is a specification.

This invention relates to crushing and grinding mills, and has particular reference to that class of mills employed in mining operations for the purpose of reducing and pulverizing mineral ores.

The invention consists, generally, in a revolving cylindrical drum or casing divided interiorly into two or more annular chambers, constructed and arranged with relation to each other, as hereinafter described and claimed, and each containing a heavy sphere or ball, which as the casing revolves rolls over upon and crushes and pulverizes the material, said material being fed in at one end of the drum and discharged at the opposite end after passing successively through its several chambers, the balls in the respective chambers being graduated with respect to the size of the chambers, or vice versa, as described and claimed, and for the purposes explained.

Specifically the invention consists in the organization, construction, and arrangement of parts to form an ore-pulverizer of the class described, all as hereinafter set forth, and more particularly pointed out in the claims.

In the accompanying` drawings, forming part of this specification, Figure l is a central longitudinal section of my improved orepulverizer. Fig. 2 is a cross-section thereof on the line 2 of Fig. l; and Fig. 3 is a perspective view of a pulverizer embodying a single compartment, to which form of machine some of the features of my invention are also applicable.

Like parts are denoted by similar letters in the different figures.

A designates a suitable base-frame, preterably rectangular in form and of any desired construction.

C denotes a power-shaft journaled in suitable boXes in this frame, the shaft being driven from any source of power through the bandewheel D or the crank D.

B B indicate heavy flanged supporting-roll ers carried by the shaft O, one of which rollers is fixed on the shaft to act as a driver for the cylindrical drum of the pulverizer resting thereon. Y denotes this cylinder. It is divided interiorly into different compartments or grinding and pulverizing chambers, of which two are shown in the drawings,A though a greater or less number may be em- 6o ployed, as the requirements of the use to which the machine is to be put may demand. The cylinder is provided exteriorly with treads or rails R, adapted in shape and size to fit the groove or ilanges of the supporting-rollers B B on the shaft O, there being advisedly one tread and support-in g roller for each grinding chamber.

Rising from the base-frame A, on opposite sides of the shaft O and the cylinder Y, are` 7o the frame-standards a, suitably braced, as shown, and preferably extending up over the cylinder and joined together at the top, forming with the base-frame a rigid structure for supporting and steadying the immense weight of the drum and its contents. The cylinder is built up, as shown in the sectional vien/,of sections iirmly secured together by bolts or otherwise, as represented, or fastened by any other means sutliciently strong to withstand 8c the great strains imposed upon the parts.

Each grinding or pulverizing chamber is in the form of an annular compartment having its inner side walls curved in the direction of the axis of the cylinder, as shown in Fig. l.

E denotes heavy metallic crushing or grin ding spheres or balls, one of Which is arranged in each compartment. These balls are proporly proportioned in size and shape tothe curve of the inner walls of the grinding-cham- 9o bers. I have found that I can produce thc best results by making these balls very much larger in proportion to the size of the grind ing-chambers than those ordinarily employed in pulverizing-machines of this general type. 9 5 There the smaller balls are used, much of the crushing effect is lost by reason of the material in the chamber covering them up and preventing the thorough Working over of the entire mass ot ore. As shown in Fig. 1, I Ito make these heavy balls of such circumferential area that they shall nearly till thec`ur`ve of the inner wall ofthe chambers, and I prefer to so construct and arrange the machine that there shall be more clearance between the surface of the ball and the side walls in the first chamber than in any ot the succeed ing chambers. In other words, the relation between the curve of the inner side walls and that of the surface of the wall in the first chamber is different from that in the remaining ones. It will be noted in the drawings that the radius ot' the sphere or ball in the second chamber very nearly equals that of the curve ot' the side walls, so that the ball tits the curve or groove pretty closely. ln the first chamber, however, it will be observed that the relation of the curves is such that there is more clearance between the surface of the ball and the curve. By reason of this construction the process of reduction or grinding of the ore is made continuous or gradual, the degree ot pnlverization in the second chamber, where the ball takes up nearly the whole of the curve, being greater than in the previous one where there is more clearance.

As shown in tte drawings, the grindingchambers communicate directly and freely with each other by central openings F, metal screensfbeing preferably provided to prevent the premature passage of the larger pieces of ore Without being properly ground.

The receiving end of the cylindrical drum is provided with the head II, made detachable and secured iirmly in place by bolts or otherwise. This head is Shaped in the form of a conic frustum to provide space on the side of the ball for the accumulation of the material to be ground, and has the feeding-opening l) in its center, into which the ore is di` rected from a suitable chute. At the opposite end ofthe drum is the dischargespout G, the general shape and construction of which are similar to that of the head Il. This discharge-spout has the opening d in the center, and may be made of foraminous material, as shown in Fig. 3, or of imperforate metal, as rep resented in Fig. l, in which latter event it is preferable to provide it interiorly with short pins or teeth g to keep the pulverized mass agitated and prevent the clogging of the throatway. The spout is advisedl y more elongated than the head II, and the object ot this construction is to provide a space for the accumulation of the pulverized material just previous to its discharge, said space having an inclined bottom down which the coarser particles of the ore are constantly settling and Working by the combined action of gravity and the centrifugal force of the rotation of the machine, the lighter particles finding their way to the top of the mass and finally passing out the opening d into any suitable receptacle.

In the operation of the machine it will be understood that the balls and the contents of the cylinder will, by reason of their friction against the inner sides of the chambers and the centrifugal torce generated bythe rotation of the cylinder, tend to climb up the ascendingside ofl the chambers. In machines like the present, where the size and weight and consequent momentum ot the grindingballs exceed that of other machines of which I am aware, this climbing of the ball andthe mass of ore contained in the chamber becomes so great that it throws the center of gravity of the entire machine out of the plane of the center of the supporting-rollers, thereby destroying the equilibrium of the machine and straining and racking the frame-work and causing considerable waste of power. Of course the higher the speed at which the machine is running the greater the displacement of its center of gravity becomes, and the greater the injury to the framing and other parts of the machine and t-he waste of power. M y invention includes means for counteracting this displacement by setting the cylinder back upon the supporting-rollers in the reverse direction to the tendency ofthe weight to leave the vertical plane ot' the center of the shaft C. In other words, I propose to adjust the position of the cylinder upon the rollers sothat the center of gravity of the mass when the machine is in action will be retained in the vertical plane pressing centrally through the supporting-rollers. To accomplish this I mount in suitable boxes X on the standards ct on each side of and abreast of the cylinder steadying-rollers B B', and these rollers are made adjustable to- Ward and from the cylinder by means of screws U, as shown in Fig. 2. It will thus be seen that the position of the cylinder may be shifted from one side to the other of a vertical plane passing through the supportingrolleis B, and that in this way the relative positions of the parts may be so adjusted as to keep the center of Weight of the moving machine and its contents in the best position for easy running and with the least strain on the frame-work.

The weight of thev crushing balls or rollers which I propose to use in this machine makes their transportation in mining districts a matter of considerable difficulty. To avoid the necessity of handling and transporting such enormous weights, with their attendant expense and danger, I provide for constructing the balls as shown in Fig. l, where the righ t-hand one is represented as composed of a hollow metallic shell having a filling of lead or any other suitable material and securely plugged. Another important advantage inherent in this construction is that by varying the character or amount ot the tilling material employedI am enabled to adjust the weight of the crushing ball or roller to the requircments of the kind and condition of the material being operated upon.

The operation of the machine is as follows: The cylinder being set in motion, the ore is fedinto the feed-opening b, and as the drum revolves the crushing-ball rolls over upon and crushes the ore by its weight. It will be un- ICO IIO

derstood that during the revolution of the drum the ooarser particles of ore, by their weight and the centrifugal action of the machine, will seek the greatest distance from the center of the chambers, which is of course the position most favorable for the effective gri nding action of the ball. The continued rotation of the cylinder carries these coarser particles around and throws them over again upon the roller, when they again find their way to the under side of the roller and are resubjected to its grinding action, this continued carrying around and throwing over of the partially-reduced portions of the mass of ore preventing undue accumulation of the material and the clogging or caking of the reduced ore upon the roller. The finer particles of the ore rise to the surface of the mass or fall from the upper wall of the drum as it revolves, and, accumulating near the center of the chamber, pass through the screened opening F into the succeeding chamber, Where the same operation is repeated. As before eX- plained, the discharge-spout is elongated for the purpose of collecting and detaining the reduced ore just after it leaves the ball in the last cylinder. By providing the space for this accumulation of pulverized material I insure the thorough working over of the mass, so that any particles of ore which may have passed through the machine without being broken up are at this point thoroughly ground. The fine dust and pnlverized material rise in this space till they reach the height of the discharge-opening d, when they pass out; but the coarse unground particles settle by their weight and centrifugal action down to the bottom of the inclined floor of the space and come again under the action of the ball. In this connection it will be observed that the discharge-opening is lower than the feedopening, and the diameter of the balls is such that their axes of rotation lie above the discharge end of the spout. This relation of parts I have found the best in practice, as it prevents the burying of the ball under the mass of ore in the chamber and insures a more effectual working over of the material.

It will of course be understood by those skilled in the art that this machine is adapted for Working upon ore in either a wet or dry condition, or hot or cold, as may be required. Then heat is to be applied during the process of pulverization in order to make the machine act as a drier and pulverizer, it should be passed by any suitable pipe or iiue into the discharge-opening and out through the feed-opening, so that the incoming ore may be gradually heated, the degree of heat being least where it enters and greatest where it is discharged from the machine.

Having thus described my invention, what I claim, and ,desire to secure by Letters Patent, isg

I. In an ore-pulverizer, the combination of two or 'more annular chambers coniniunioat ing with one another, a metallic sphere or roller in each chamber, a feed-opening in one of the chambers and a discharge-opening in the opposite chamber, the interior contour of the walls of one chamber conforming more nearly to the size and shape of its sphere or roller than those of the preceding chamber, substantially as described.

2. An ore-pulverizer consisting of a cylindrical drum or casing, said casing being provided interiorly with two or more annular chambers communicating with one another by central openings covered With suitable screens, an iron sphere or roller in each chamber, the interior contour of the walls of one chamber conforming more nearly to the size and shape of its sphere or roller than those of the preceding chamber, centrally-arranged feeding and discharging openings at opposite ends of the machine, and means for imparting an axial rotation to the drum, substantially as described.

In an ore-pulverizer, a cylindrical drum or casing having its interior divided transversely into annular chambers communicating with one another by central openings, and each chamber having its inner side walls curved in the direction of the axis of the cylinder, and spherical balls in the several chambers, the curve of the walls of one chamber conforming more nearly to the circumference of its ball than that of the preceding chamber, substantially as described.

4. In an ore-pulverizer, the combination, with the base-frame, the power-shaft journaled therein, and the hanged supporting and driving roller carried by the shaft, of the cylindrical drum or casing seated upon the roller, the standards rising from the baseframe on opposite sides of the drum, and the steadying-rollers mounted in the standards abreast of the drum and adjustable, as de'- scribed, for the purpose set forth.

5. In an ore-pulverizer, the combination, with the base-frame, the power-shaft journaled therein, and the flanged supportingrollers carried by the shaft, of the cylindrical drum or casing divided transversely into grinding-chambers, as described, and having the treads seated between the flanges of the rollers, the standards rising from the baseframes on opposite sides of the drum and joined together at the top, forming an arch, and the adjustable steadying-'rollers carried by the standards abreast of and on opposite sides of the drum, substantially as described.

In testimony that I claim the foregoing as my own I have hereto ai'iixed my signature in presence of two Witnesses.

SAMUEL BENSON.

Witnesses:

J. C. F. WooDWoRrH, J. M. MONTGOMERY.

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